The present invention relates to a bowl for a centrifuge for clarifying or separating mixtures of liquids, with a valve or slide that is maintained in the closure position by a closure fluid, which circulates at the same angular velocity as the bowl, and that is associated with a closure chamber containing the closure fluid.
A centrifuge bowl of this type is known from U.S. Pat. No. 3,250,463. The extraction channels that extend in the jacket of the bowl from the solids space are closed off with a piston slide. A closure chamber that can be filled with closure fluid from a supply line is associated with the piston line. Runoff bores extend radially out from the closure chamber through the jacket of the bowl. Closure fluid always emerges from these bores while the piston slide is in the closure position, and the lost fluid must be replenished. The opening motion of the piston slide is initiated by adjusting the supply of closure fluid to the closure chamber, allowing the closure fluid in the closure chamber and supply line to flow out through the runoff bores subject to centrifugal force. To discontinue the opening motion of the piston slide, fluid is again introduced into the closure chamber through the supply line, generating a closure force in the closure chamber that shifts the piston slide into the closure position and maintains it there.
Since the closure chamber must be emptied to initiate the opening motion and filled with closure fluid again to initiate the closing motion of the piston slide, the known system of controls is relatively sluggish. Furthermore, since closure fluid must be constantly supplied to the closure chamber during the closure phase, more fluid has to be consumed.